Once fruits, vegetables and flowers are harvested, they are vulnerable to spoilage and must be consumed within a certain period of time. Some fruits and vegetables, for example, apples, can be stored under cold conditions for long periods without spoilage. Most fruits and vegetables, however, are perishable and cannot be stored for protracted periods.
Studies have been made of the mechanism of senescence and post-harvest deterioration. Membrane deterioration mediated by lipoxygenase has been identified as an early manifestation of the onset of senescence. Senescence is accompanied by the evolution of ethylene and once ethylene evolution commences, the process of deterioration is accelerated.
The biosynthetic path to ethylene formation has been identified as initial conversion of methionine to S-adenosyl methionine (SAM), the conversion of SAM to 1-amino-cyclopropane-1-carboxylic acid (ACC), and thence to ethylene.
It has previously been observed that the cytosol fraction from extraction of the petals of senescing carnation flowers inhibited ACC to ethylene conversion activity of membranes isolated from the petals (Mayak et al, Planta (1981) 153:49-55).
We have now been able to isolate and identify the active material which provides the inhibition and have identified a class of compounds which are useful in the inhibition of ethylene production in vitro and in situ from harvested fruits, vegetables and flowers.